Demand for light emitting diodes (LEDs) has expanded exponentially in terms of low power consumption and environmental friendliness. LEDs are used as backlights for lighting apparatuses and LCD devices and are widely applied to display devices.
LEDs are kinds of solid-state elements that convert electrical energy into light. LEDs are based on the principle that when a voltage is applied between two doped layers, i.e. an n-type semiconductor layer and a p-type semiconductor layer, between which an active layer is interposed, electrons and holes are injected into and recombine in the active layer to emit light. LEDs can be driven at relatively low voltage and have high energy efficiency. Due to these advantages, LEDs release a small amount of heat. LEDs can be produced in various types. Particularly, micro-LED array display devices are fabricated based on types of LEDs in which a plurality of micro-LED pixels are formed on one wafer. According to a conventional method for the fabrication of a micro-LED array display device in which a plurality of micro-LED pixels are formed on one wafer, a p-type terminal and an n-type terminal are formed in each pixel through a chip production process and are arrayed along the longitudinal and transverse axes of signal lines to drive the pixel. In this case, elements responsible for signal control in the micro-LED pixels should be disposed in the vicinity of the micro-LED pixels, resulting in an increase in the size of the micro-LED array display device. Further, data lines arrayed along the longitudinal and transverse axes should be connected to the micro-LED pixels by wire bonding, making the process complicated and inconvenient.
The formation of a plurality of micro-LED pixels on one substrate technically limits the production of structures emitting red, green, and blue light. Because of this technical difficulty, the use of LEDs as light sources in micro-LED array display devices inevitably leads to the emission of monochromatic light. Thus, there is a need in the art for an approach that can provide a solution to the problems of the prior art.